Internal engine issues

OK I don't have a lot of internal engine experience so here's the story and pictures to get some opinions.

One piece rear main block. My "friend" had it in his truck when he bought it a few years back. Always had a rapid tick. Sounded like upper end but a little deeper sound. He put vortecs and a roller cam in it. No change. Took the lower end apart and didn't see anything, put rod bearings in it this summer. No change. He finally pulls the plugs one at a time and gets a big change in the noise on number three.

I trade him for it and take it apart hoping it's a wrist pin and the inside is as good as he described.

I pop out number three and notice the bearings. They look like there is too much wear and wildly uneven for just a few thousand miles to me. Look at the pictures and tell me what you think. The pictures are of #3 and #4.

The wrist pin on three sticks as you rock the rod in the piston. The more you move it the smother it feels but is still sticks. The rod in number 4 is smooth as silk.

All bores are smooth as glass. No signs of cross hatch what so ever. Again I'm thinking this is bad. I haven't measured the bores or pistons yet. I have to borrow the tools. The pistons are marked for 30 over. I can feel some unevenness on the crank journal.

I need this going soon. It's going to be a daily driver. I was hoping to get off cheap.

Pictures:

http://i191.photobucket.com/albums/z40/Knuckle_Dragger/DCP01664.jpg

http://i191.photobucket.com/albums/z40/Knuckle_Dragger/DCP01665.jpg:mad:

Well if it were me, I would mic the crank and check the rods for big end size.

If the crank checks good I would certainly polish it. The bearings dont look very good, but I doubt thats the noise.

It may well be the piston. Some times a scored pin bore will cause a knock.

I would mic the piston skirts in about 3 places, all 90 degrees to the pin bore. 1 level with the pin bore, another about 1/2 way down the skirt, and one at the tip of the skirt. In my experience on that engine the piston should be about .001' larger at the tips of the skirt than it was at the pin bore.

I would bore gage the cyls for size and taper out of round etc..

I would think a "normal" cyl wall clearance measured at pin bore would be .001"-.002"? I would check a manual for sure.

Your noise could well be in the piston, but I would certainly service the bearings while you are there.


Good Luck

Jeff

no cheap fix unless you want to screw someone,

Sounds time for a crank turn and a hone,,,possible bore

I agree with Jeff. Measure everything to see where you are at and what needs to be done. My experience is if you try to short cut the problem, you may be taking it apart again.

Usually when it's worn on the upper bearing like that it's a sign of detonation. That could explain the ticking noise also....Or it could be improper roundness on the big end.

One thing that struck me about what you said was the tick got worse after the plugs where changed.

Two things can tick like an engine tick. Header or exhaust leak and plug wires arcing...or maybe not.

To solve this you'll need to make a list, check off everything until you find the problem.

Another tick noise could be the fuel pump ticking against the push rod. It happens when the pump spring gets weak and it sounds like a lifter. Dave

I agree with Jeff. Measure everything to see where you are at and what needs to be done. My experience is if you try to short cut the problem, you may be taking it apart again.

Usually when it's worn on the upper bearing like that it's a sign of detonation. That could explain the ticking noise also....Or it could be improper roundness on the big end.

One thing that struck me about what you said was the tick got worse after the plugs where changed.

Two things can tick like an engine tick. Header or exhaust leak and plug wires arcing...or maybe not.

To solve this you'll need to make a list, check off everything until you find the problem.

The noise decreased when the #3 spark plug wire was pulled.

I think the only cheap out on this is going to be to do it right so I don't do it again. After sleeping on it I think it's going .040, crank polished or turned and re size the rods and ARP bolts. I guess all I got worth a crap were the newish vortec heads.

I would not panic untill you do some checking.

The ARP bolts and rod resizing is about always a good option in my opinion.

Why pump to .040" over? Is it already .030" or something?

I would measure stuff first. It may need be nearly that bad.

I have repaired similar issue in passenger engine by simply honing a pin bore and installing an oversize pin.

If the pistons and cyls check out, it my not be a big deal.

The block is still worth money :P

Just have the crank checked (turned/polished) bore/hone the block, and you may even want to do an align hone.

Well I got all the pistons out. Three or four pins bind. All the bearing look about the same. I pulled one main and it looked pretty good. I can get the crank out because my damper puller is at work.

I'm concerned with the way the rod bearings are worn. a few of them are badly worn on one side or another. #7 was into the copper. #7 and 8 are burning oil based on what I see on the top of the piston.

I'll get it completely apart and cleaned up enough I feel safe transporting it in momma's Expedition tomorrow. It will hit the machine shop on Wednesday for another set of eyes. I feel better having a guy who measures this stuff all day long take a look. I've wrenched for 20+ years but only built a handful of engines.:(

It looks like those rods have arp bolts or similar judging from the centering points for a rod stretch guage. I would measure the bores and if they're alright just deglaze them and ready it for new rings. Toss some new cam bearings in at the same-cheap. Have the crank and rods checked out, resize the rods if necessary and order up a new set of pistons-hyperutectics are economical enough or even some cast claimer type will work fine. New rings gapped properly also. If the crank needs to be turned just scrap it and buy a new scat replacement for almost the same price as a regrind. The balance will be close enough considering the pistons are +.030 already-or add $150-$200 to the bill and have the whole rotating assembly balanced.